Sebastian Vettel said a lack of consistency from the Pirelli tyres has prevented Red Bull completing all its set-up work during pre-season testing.

Mark Webber only completed 58 laps on Saturday, and while Vettel racked up 100 on the final day it still left the team well short of the likes of pace-setting Mercedes which completed 248 laps over the weekend. Vettel admitted that the lack of track time and issues with Pirelli tyres left the team's testing schedule incomplete.

"We would love to have had the opportunity to work more on the set-up and read the changes but the tyres were not very consistent so I think everyone was struggling with that," he said.

However, Vettel was keen to stress he is still optimistic for Australia and that it was more a general problem from testing.

"Definitely look forward. Testing was good for us as a whole but surely we would have loved to have had more consistency. Especially from a tyre point of view, I think all the teams suffered the same kind of problem, therefore it was difficult to really read the changes and the steps that we tried to make but that's how it is."

With stability in the regulations, Vettel said he still felt the car was likely to be heavily improved in Australia.

"You always tend to think that [there won't be big gains]but then the people from the aero department turn out with some new parts and there's always going to be a step. I think the target is there to really improve the car by a lot, use the time in the races that we have but for now for sure it's to understand a little bit more with the new parts that we put on the car and find the right direction."